[OMEGA412]

Originally Posted by suspect

600Nm?

Ft /lbs sorry

[ab987]

Originally Posted by Quick335XI

Wow, makes me so sad to read this! I will NEVER own another sports car without 1) AWD and 2) A MANUAL transmission. I can't imagine why anyone would go thru the trouble of de-evolving down to an auto from a manual!! 6sp'd are so hard to find too. Unbelievable!

Definitely plenty of manual things happening to make the 8AT work, like writing code to make it do what we want I do think I'll end up swapping back in the 6MT though once I can find some new seals. JonOhh has the car now and is experimenting a bit more with the 8AT before we throw in the towel.

I would hardly consider my E93 to be much of a sports car anyways, it's more of a top-down cruiser that can do some hilarious rolling burnouts. But I am missing a 6MT in my life...

[AshwinLB]

Oh man I really wish this would have worked out. I used to have a 6AT 135i and it was so much fun on the street with its ability to be a missile at a moments notice. I have a 6MT now and while it’s even more fun than the 6AT on the track, I don’t particularly enjoy it as much on the street. This truly would have been the best of both worlds. Hopefully this project becomes more feasible in the future

[JonOhh]

Originally Posted by Quick335XI

Wow, makes me so sad to read this! I will NEVER own another sports car without 1) AWD and 2) A MANUAL transmission. I can't imagine why anyone would go thru the trouble of de-evolving down to an auto from a manual!! 6sp'd are so hard to find too. Unbelievable!

Eh, we still have the 6MT to throw back in if we want - and that may happen some day. We did it in a reversible way, we even left the clutch pedal in (it rests against the floor).


There's pros and cons to the 6MT, and we both get that. The MT is certainly fun, and quite enjoyable but at least personally, I found it much less satisfying and enjoyable than my 6MT 330i as a result of the weight of the E93, and how lazily the N54 responds to throttle request changes (especially with big twins) in comparison to the NA N52. (Though on that last point, not all of that is the result of the N54 itself...the MSD80/81 have some absolutely horrendous throttle damping that really kills any level of engaging throttle response after getting used to an NA car. It can be turned off in the tune to make it much, much better, at the very least.

An auto trans with a huge ratio spread (huge fuel economy gains), the ability to shift seamlessly during city driving, and the ability to shift so aggressively that it can break the rear end loose at 80 MPH, is the best of both worlds IMO, especially if the MT control works out as it has the ability to.

However, the TCU we chose kinda blows. So until we get the motivation and time to make our own, the car is just "alright". In its current state, we definitely miss the 6MT, but if the ZF8 was operating at its full potential, I'm quite certain we wouldn't.

[Effort]

I made an account just to say thank you two so much, this is an invaluable set of information for my own swap of the GA8P75HX into a 4x4. People ragging on the auto swap really are missing out on how badass the ZF really is.

I had benched the 8p70 idea in favour of an 8hp70 until I found this thread due to complexities with everything but this all makes a ton of sense and between this and FuelTech's new support for Inverter control the dream is back to life which I'm sure will contribute to the near term demise of my sanity
I'm already doing an entire vehicle harness, engine + gearbox mounts from scratch may as well throw a full hybrid drive system in while I'm at it right?

My goal in adding hybrid is really just things like range extension, particularly in the city (petrol v8), additional energy generation for camping and maybe some neat things like an electronically braked crawl control on descents in the distant future.

I expected that the turbolamik wouldn't work and would be a pita to integrate with a separate electric motor drive along with the additional motor controls needed for the low speed oil pump that only the hybrid has. Thank you for saving me that expensive headache in finding out its basically useless for the hybrid! I didn't need features like fake clutch pedal and trans brake for my application, but they would have been cool to have anyway and I don't think I would bother implementing them if I roll my own.

The video posted where ZF details differences was full of gems. It would explain why you're getting such crappy shifts in the lower gears, since it has that additional clutch and was designed to rely on the auxiliary oil pump to give it pressure at low rpms. I'm guessing it just doesn't have enough gearbox rpm to make the pressure required with that additional clutch plate and grabs harshly without the having the designed oil flow between 0 rpms and whatever range the main oil pump takes over. I wonder if they have changed the main shaft driven oil pump too since they could make it more efficient for a higher rpm range since they've already got the electric pump doing fill in on the low end.
I'm guessing extra vein on the oil drain is related to the different cooling path introduced for the larger "B" clutch assembly? With the extra oil flow I can see it having a different set of drainage requirements.

Very interested in the open source controller idea. I have tons of programming experience but on a tiny amount of that is with embedded devices/micro controllers so that was going to be a rough start up for me and I could just see the complexity getting out of hand to get all these systems working together nicely. I figured I would need to make my own tcu with integrated motor/inverter controls to run something like a prius inverter/controller as I've on other hybrid swaps (projects like stm32-vcu by Damien Maguire, stm32-sine by Johannes Huebner). But if you're working on a opensource TCU for the 8P/8HP I can dump that idea and try use the inverter out of an 330e M-sport, x5 or 7 series hybrid and try control it all over CAN with a FuelTech to get it a little closer to an OEM setup. And the FuelTech guys seem like they would actually actively support wacky projects like this so they can improve their stuff.
My original plan was to get a stock TCU and scope/log out all of the sensors and use a big servo to spin it through the entire operation range to make a rough model of how/when everything is actuated as a starting point to work from. I had asked a company CAN TCU about them supporting it but based on the differences in reluctor wheels and stuff like that I think that's probably a long shot.

If you have any technical docs specific to the 8p70 would you mind sharing? I've only been able to find docs for the 8hp so far.

If there's a github or anything for the basic diy TCU setup you guys have going I'd love a link so I can circle back and contribute when life allows.

[Chris GA8P70HZ]

I also just joined to learn from OP about this transmission. This thread is a gold mine of essential information. I've read it all many times.

Bought the same one a while ago. 8HP boxes are rare in Thailand so I snapped this one up. I plan to swap it into a W124 with M104 turbo. The car runs but blew up the 722.3 trans. I want an 8HP on advice of a BMW friend of mine, LaimisBMW.

The trans is from an F30 N55 GA8P70HZ Active hybrid. My ECU is MaxxECU Sport so will do their reflash of TCU and connect via CAN. The TCU Bosch PN matches the ID for 8hp70 TCU. Will get an F10 shifter most likely and custom adapter kit from Jota5Sport.

Questions are:
Is the P2 planet with magnets essential to run this trans? I can live without 1st and 2nd.
If yes, can the P2 gear be swapped without pulling out the drum? I've watched disassembly videos and read the manual.
You say it shifts fine but something is off.
Is any torque converter from the 45 with flat flange OK to use?

Really hope ab987 answers. You rock, man